Hooking up a VR when....

...you have no idea where/what the wires on the tractor are. The tractor is a 1957 Cub Loboy. I have a new regulator. The old one was in bad shape. At the time I took it off I am pretty sure that I made a chart of the wires but...oops. At that time I also installed a nice new harness. Pretty sure the instructions for that are in the same place the chart is...somewhere "safe" that I will never forget.

I have four terminals on the VR and three wires on the tractor where the old VR was. The terminals on the VR are "L", "BAT", "FLD" and "GEN". The wires I have are black, green, and gray. The black wire is shorter than the others and I THINK it goes to the GEN terminal as it comes down from the generator. Scratching my head on the rest. Thinking BAT means battery. The FLD I am pretty sure means field...but I have no idea what a field is. The L??? No idea...lights maybe? Pretty much thinking I have to trace back the gray and green wires and that they will be BAT and FLD. I am hoping the BAT wire will trace back to the battery gauge on the dash. Right? Where would a FLD wire trace back to? Any help not frying my new VR would be hugely appreciated. The directions included are pretty poor.

The regulator attaches as follows:
The Field terminal on the generator (Marked with an "F") attaches to the FLD terminal on the new regulator. It can be a 12 gauge wire. The Gen terminal on the Regulator attaches to the "A" terminal on the Generator, should be 10 gauge wire (Might say ARM). The Bat terminal on the Regulator attaches to the load side of the amp gauge. It should also be 10 gauge. The L terminal (the troublesome one) can be attached to a new wire (10 gauge) that supplies the lights, or other accessories. The original Wire to the lights from the load side of the amp meter, can be disconnected from the amp meter if you do this. The "L" wire can also be hooked to the Bat wire at the regulator with a short 10 gauge wire (simple solution). The regulator is set up this way to supply a more closely regulated charging voltage to the battery. However in the case of a Lowboy it will make little difference. Jim

I'm sure some of the good IHC gents will post a wiring diagram but in the meantime:

4 Terminal (BAT FLD LOAD ARM)
BAT wires to the Load (NOT battery supply) side of the ammeter
FLD wires to the Gennys FLD post
ARM (GEN) wires to the Gennys ARM post
LOAD feeds hot battery voltage up to the lights and ignition such as the bat input terminal on a lights or ignition switch

3 Terminal (BAT FLD ARM)
BAT to load side of ammeter
FLD to gennys FLD post
ARM (GEN) to gennys ARM post

IN THE EVENT YOU HAVE A NEW 4 TERMINAL VR TO REPLACE AN OLD 3 WIRE VR and only three wires available to connect:

BAT is the one that's hot voltage because its connected to the load side of the ammeter
FLD on VR still wires to gennys FLD post
GEN on VR still wires to gennys ARM post

You can either disregard and not use L orrrrrrrrrrrrr you can use it to feed the lights and ignition which used to be fed off the ammeters load side terminal, same terminal where BAT from VR connects. On a factory 4 wire system loads are fed off the LOAD terminal,,,,,,,,,On a factory 3 Wire system loads are fed off the load side of ammeter, that's the same place where BAT from VR is connected

On a genny FLD is often the smaller post and ARM is often the bigger one.

A 3 can be converted to a 4 or a 4 to a 3 wire if you follow the above

To be safe Id polarize the genny BEFORE start up

Check the wiring diagrams and what the IHC experts have to say

John T

(quoted from post at 17:50:48 06/23/19) ...you have no idea where/what the wires on the tractor are. The tractor is a 1957 Cub Loboy. I have a new regulator. The old one was in bad shape. At the time I took it off I am pretty sure that I made a chart of the wires but...oops. At that time I also installed a nice new harness. Pretty sure the instructions for that are in the same place the chart is...somewhere "safe" that I will never forget.

I have four terminals on the VR and three wires on the tractor where the old VR was. The terminals on the VR are "L", "BAT", "FLD" and "GEN". The wires I have are black, green, and gray. The black wire is shorter than the others and I THINK it goes to the GEN terminal as it comes down from the generator. Scratching my head on the rest. Thinking BAT means battery. The FLD I am pretty sure means field...but I have no idea what a field is. The L??? No idea...lights maybe? Pretty much thinking I have to trace back the gray and green wires and that they will be BAT and FLD. I am hoping the BAT wire will trace back to the battery gauge on the dash. Right? Where would a FLD wire trace back to? Any help not frying my new VR would be hugely appreciated. The directions included are pretty poor.

Click to expand...

Here's a link to a service manual for Cub electrical equipment, which may be of some help, although, I'll not sure if it is correct to the age of your Cub.

You will have to copy the link and paste it into your browser, as it will not post as a clickable link here.


http://farmallcub.com/rudi_cub/www.cleancomputes.com/Cub/Blue%20Ribbon%20Service%20Manuals/GSS-1012%20Electrical%20Equipment/index.html

Much appreciated guys! I will print these out and use for reference. I'm thinking I will pull the hood off and make sure it is right. Then I can see the genny and gauges.